1. Field of the Invention
An aspect of the present invention relates to an image forming apparatus and an image reading apparatus. More specifically, an aspect of the present invention relates to an image forming apparatus and an image reading apparatus in which movable objects (for example, an image reading unit, an opening/closing member, a recording material cassette, and the like) are locked so as not to move when a product is shipped, and a locking structure is automatically released when the product is unpacked and used for the first time by a user.
2. Description of the Related Art
Conventionally, apparatuses such as a digital photocopier, a facsimile machine, a printer, and a multifunction device having an image reading section, an image forming section, and an automatic document conveyer are known.
The image reading section is a device for reading image information of supplied documents, and the image forming section is a device for printing images on recording materials based on the image information read by the image reading section. The automatic document conveyer is a device for supplying documents one sheet at a time to a reading position of the image reading section, and ejecting documents to a document ejection tray after the documents have been read.
FIG. 1 shows a configuration of a conventional image forming apparatus disclosed in Japanese Unexamined Patent Application Publication No. 10-293431 published on Nov. 4, 1998, and FIG. 2 is a perspective view showing a configuration of an image reading section of the image forming apparatus in FIG. 1.
Referring to FIG. 1, an image forming apparatus includes an image reading section 1s for reading images of documents S and B, and an image forming section 1p for forming images on recording materials based on the image information read by the image reading section 1s. 
A pressing panel 1 is installed on a frame 2 with hinges 1h to rotate through a certain angular range about a hinge axis 1g. 
Referring to FIG. 2, a document stacking tray 1c is provided on the top of the pressing panel 1 in order to stack documents S. A document ejecting conveyer 5 is provided at the upper portion of the pressing panel 1. The document ejecting conveyer 5 includes a preliminary conveyance roller 1d and a preliminary conveyance pressing panel 5a for conveying the documents S from the document stacking tray 1c, and a separating pad 5b and a separating roller 1e for separating the documents S that are conveyed by the preliminary conveyance roller 1d and the preliminary conveyance pressing panel 5a into individual sheets. In addition, the document ejecting conveyer 5 includes a document feed roller if and a paper feed roller 5c for feeding the documents S to a reading unit 6, with the paper feed roller 5c being pressed against the document feed roller if by a pressing panel spring (not shown).
A contact image sensor 4 is installed at a curved portion of a conveyance path, and a document pressing roller 5d for pressing and conveying the documents on the conveyance path is installed opposite the contact image sensor 4. The document pressing roller 5d is elastically pressed by a press spring 5i in the direction of the conveyance path, and if a document S enters the reading unit 6, the document S is pressed by the document pressing roller 5d and conveyed while being in contact with a document base glass 2a. 
The image reading section 1s described above can operate in either a flat-bed mode in which a stationary document is read, or a sheet-through mode in which a moving document is read.
In the flat-bed reading mode, a document B is placed on the document base glass 2a, and when the pressing plate 1 is rotated about the hinge axis 1g, the document B is pressed against the document base glass 2a. Then, the contact image sensor 4 moves in the direction of the arrow A, and reads an image of the document B placed on the document base glass 2a. 
In the sheet-through reading mode, the contact image sensor 4 stands still at the position of the reading unit 6 and reads an image of a moving document S. The documents S placed on the document stacking tray 1c are first conveyed by the preliminary conveyance roller 1d and the preliminary conveyance pressing panel 5a, and are then separated into individual sheets by the separating roller 1e that is in contact with the separating pad 5b. Thereafter, the documents S are conveyed to the reading unit 6 by the paper feed roller 5c against which the document feed roller If is pressed by the pressing panel spring.
At the reading unit 6, the documents S are conveyed while being in contact with a surface of the document pressing roller 5d, and images of the documents S are read by the contact image sensor 4. The document pressing roller 5d is elastically pressed in the direction of the conveyance path by the press spring 5i, and prevents the documents S from floating on the document base glass 2a. 
FIG. 3 shows an example of an image forming apparatus with a locking device 20 that holds an image reading sensor, such as the contact image sensor 4 described above, so that it does not move.
The image forming apparatus in FIGS. 1-2 described above uses a locking device 20 as shown in FIG. 3 to hold the contact image sensor 4 so that it does not move when the image forming apparatus is shipped.
Accordingly, a user can use the image reading section 1s only after the locking device 20 is released. If the locking device 20 is not released due to a user's mistake, the image reading section 1s cannot be used properly, and if serious problems occur as a result, service must be called for.
Conventionally, only a locking device 20 for locking an image reading sensor is provided. However, an image forming apparatus includes several easily movable parts, such as the pressing panel 1 and an opening/closing member for opening/closing the image forming section 1p described above, a recording material cassette for supplying recording materials on which images are printed based on the image information read by the contact image sensor 4, and the like. Therefore, in order to prevent the easily movable parts described above from moving when the image forming apparatus is shipped, packing materials must be carefully selected, and special fixing materials must be additionally attached to fix the easily movable parts in place to prevent them from moving.